This invention relates generally to bar codes readable with optical readers. In one aspect, it relates to a unique bar code for encoding machine-readable information.
With the growing numbers of computer users connecting to the xe2x80x9cInternet,xe2x80x9d many companies are seeking the substantial commercial opportunities presented by such a large user base. For example, one technology which exists allows a television (xe2x80x9cTVxe2x80x9d) signal to trigger a computer response in which the consumer will be guided to a personalized web page. The source of the triggering signal may be a TV, video tape recorder, or radio. For example, if a viewer is watching a TV program in which an advertiser offers viewer voting, the advertiser may transmit a unique signal within the television signal which controls a program known as a xe2x80x9cbrowserxe2x80x9d on the viewer""s computer to automatically display the advertiser""s web page. The viewer then simply makes a selection which is then transmitted back to the advertiser.
In order to provide the viewer with the capability of responding to a wide variety of companies using this technology, a database of company information and Uniform Resource Locator (xe2x80x9cURLxe2x80x9d) codes is necessarily maintained in the viewer""s computer, requiring continuous updates. URLs are short strings of data that identify resources on the Internet: documents, images, downloadable files, services, electronic mailboxes, and other resources. URLs make resources available under a variety of naming schemes and access methods such as HTTP, FTP, and Internet mail, addressable in the same simple way. URLs reduce the tedium of xe2x80x9clogin to this server, then issue this magic command . . . xe2x80x9d down to a single click. The Internet uses URLs to specify the location of files on other servers. A URL includes the type of resource being accessed (e.g., Web, gopher, FTP), the address of the server, and the location of the file. The URL can point to any file on any networked computer. Current technology requires the viewer to perform periodic updates to obtain the most current URL database. This aspect of the current technology is cumbersome since the update process requires downloading information to the viewer""s computer. Moreover, the likelihood for error in performing the update, and the necessity of redoing the update in the event of a later computer crash, further complicates the process. Additionally, current technologies are limited in the number of companies which may be stored in the database. This is a significant limitation since world-wide access presented by the Internet and the increasing number of companies connecting to perform on-line E-commerce necessitates a large database.
Many types of optical readers are known, however, their cost and complexity have heretofore limited their use primarily to industrial and commercial users. Now, many new network-based technologies are being developed for home users which involve optical scanning. Thus, a need exists for a simple, low cost optical reader which can be attached to a personal computer.
Many types of bar codes are known for encoding machine-readable information in accordance with existing standards, for example Code 128, EAN 128, Codabar, the EAN 8 and 13 series, the ISBN series, the ISSN series, ITF, the JAN 8 and 13 series, Pharmacode, the UPC-A and -E series, Plessy and Code 39. Such bar codes are used for a variety of commercial purposes including inventory control, retail sales, shipping information, etc. For a number of reasons, including the expansion of computer-based commerce and network-based commercial activities, a need exists for new bar codes which can be distinguished from existing bar codes.
Low cost optical readers which can be attached to personal computers will increase the number of persons having access to bar code technology. However, a relatively small percentage of the public is actually trained in the use of such equipment. A need therefor exists, for bar codes which facilitate accurate reading by inexperienced users.
The present invention disclosed and claimed herein comprises, in one aspect thereof, a bar code for encoding information in machine-readable form. The bar code comprises a character string including a plurality of characters disposed side-by-side along a longitudinal code axis. Each character is formed by a sequence of code bars and intervening code spaces, the code bars being parallel to one another and to a line defining a bar axis which intersects the code axis. Each character has a definition in accordance with a predefined standard. The definition for each character includes a bar/space pattern associated with the character setting forth the respective widths of the code bars and code spaces making up the character in terms of integer multiples of a minimum unit width. The definition for each character also includes at least one encoded alphanumeric value associated with the character. The definition for each character further included an integer checksum value associated with the character. The plurality of characters in the character string includes, sequentially, one start character, at least one message character, one check character and a stop character. The bar axis forms a slant angle with a line perpendicular to the longitudinal code axis, and the slant angle has a value greater than about 1 degree.